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1925] Setchell-Gardner: Melanophyceae 481
The species under consideration has a relatively extensive system of
creeping filaments but very much less so than that of a typical Comp-
sonema. The creeping filaments do not form a solid disk, but those
from different plants are so intertwined that it is impossible to deter-
mine the limits of a distinct individual. In this character it resembles
an Ectocarpas. The gametangia are like those of a typical Ectocarpas,
but since they are mostly short-pedicellate and spring directly from
the creeping filaments, as is the case in a typical Compsonema, and
because of the relatively extensive system of creeping filaments, we
have placed it in the latter genus.
11. Compsonema streblonematoides S. and G.
Fronds forming thin, circular cushions, 3-5 mm. diam. ; prostrate
portion composed of filaments following closely the irregularities of
the host, giving rise below to numerous rhizoidal filaments penetrating
to a depth of 300-350/*. among the cells of the host, and above to sterile
filaments and gametangia; erect filaments 140-160/* long; cells of
erect filaments cylindrical. 8.5-10/* diam., 1.5-3 times as long ; zoo-
sporangia unknown; gametangia mostly cylindrical, short-pedicellate,
55-70/x long, ll-14/i broad ; loculi mostly 2-seriate.
Growing on the pneumatocysts of Nereocystis Luetkeana. Mouth
of Tomales Bay, Marin County, California.
• Setchell and Gardner, Phyc. Cont. Ill, 1922, p. 353, pi. 35, fig. 4.
Compsonema streblonematoides, like a Streoloncma, has a large
part of the vegetative portion of the frond within the host -plant, the
penetrating filaments extending into the host two or three times as far
as the length of the external vegetative filaments. The whole frond,
however, is the result of the growth of a single cell and forms a com-
pact monostromatic basal disk. In the character of the gametangia it
is close to a Myrionema, but in a very large majority of cases the
loculi are biseriate.
12. Compsonema sporangiiferum S. and G.
Fronds forming circular cushions, 1-4 mm. in diameter; prostrate
portion composed of compact, irregular, more or less contorted fila-
ments following the irregularities of the surface closely, monostro-
matic or in part distromatic ; erect filaments 300-700/x long, un-
branched or bearing above a few short, mostly secund, fructiferous
ramuli ; cells of the erect filaments 6-8/*. diam. at the base, and 2-3